Suspended crowns of industrial furnaces, and refractory elements for making such crowns

ABSTRACT

A suspended crown of an industrial furnace formed of anchored refractory bricks, additional refractory bricks, and refractory plates. The anchored bricks are formed at one end with means for engaging hooks which secure the bricks to support beams, and at their opposite ends with shoulders for carrying the refractory plates. The sides of the anchored and additional bricks are formed with teeth which mesh with teeth in adjacent bricks. The plates are generally rectangular and provided with parallel channels for reducing their weight.

United States Patent [191 Palazzo SUSPENDED CROWNS OF INDUSTRIALFURNACES, AND REFRACTORY ELEMENTS FOR MAKING SUCH CROWNS [75] Inventor:

[73] Assignee: S.I.R.M.A. Societa Italiana Refrattari MargheraAzionaria, Venice, Italy 22 Filed: Mar. 8, 1974 21 Appl. No.: 449,424

Ferdinando Palazzo, Venice, Italy [30] Foreign Application Priority DataMar. 22, 1973 Italy 67821/73 [52] U.S. Cl. 110/99 R; 432/247 [51] Int.Cl. F23m 5/02 [58] Field of Search 110/99 R, 99 A; 432/247 [56]References Cited UNITED STATES PATENTS Liptak ll0/99 R [451 Apr. 15,1975 1 H1953 Forsyth 110/99 R 10/1962 l-Iosbein et a]. 110/99 R PrimaryExaminer--.Iohn .I. Camby Attorney, Agent, or Firm-Breitenfeld & Levine[57] ABSTRACT A suspended crown of an industrial furnace formed ofanchored refractory bricks, additional refractory bricks, and refractoryplates. The anchored bricks are formed at one end with means forengaging hooks which secure the bricks to support beams, and at theiropposite ends with shoulders for carrying the refractory plates. Thesides of the anchored and additional bricks are formed with teeth whichmesh with teeth in adjacent bricks. The plates are generally rectangularand provided with parallel channels for reducing their weight.

6 Claims, 18 Drawing Figures PATENTEDAPRISIQYS SHEET ug g SUSPENDEDCROWNS OF INDUSTRIAL FURNACES, AND REFRACTORY ELEMENTS FOR MAKING SUCHCROWNS The present invention relates to improvement concerning thesuspended crowns of industrial furnaces, and refers specifically torefractory elements intended to form said crowns.

The use of suspended crowns formed by refractory bricks having aparticular shape is known. Some of the bricks are hooked to load bearingbeams, while others are so shaped as to permit assembly with each otherand with the first mentioned bricks in order to form partiallyself-supporting crown assemblies.

It is also known that in the design of the suspended crowns the thermalexpansions of the elements used must be taken into account, as saidelements are not only subject to premature wear but, although they aremade with a suitable and accurately selected material, they are alsosubject to possible breakages, flaws, and cracks deriving from theinternal stresses cuased by the thermal effect to which the structuralelements are subjected.

The main object of the present invention is to provide, as a newindustrial product, suspended crowns for industrial furnaces in general,which can be quickly assembled and formed by modular elements easilyreplaced in the case of damage or wear.

Another object of the invention is to prrovide suspended crowns formedby bricks combined with refractory plates, the latter having a specialsurface and being therefore suitable for rapid construction of suspendedcrowns, even of great expanse.

With the aforesaid objects in view, the improvement according to theinvention is substantially characterized in that the suspended crownstructure comprises three basic modular elements, that is:

a. Anchored refractory bricks, substantially prismatic and provided atone end with holding means for metal hooks engaged with load bearingbeams, while the opposite end is so shaped as to provide small bearingshoulders for refractory plates; the pair of opposed sides of saidbricks being respectively provided with symmetrical grooves and teeth;

b. Refractory bricks which are complementary and analogous to theanchored bricks, but not provided with holding means for hooks; and

c. Refractory plates having a substantially rectangular shape in planand a pair of parallel sides so shaped as to form bearing edges, withrespect to the brick shoulders, and ordered in parallel rows, while theother pair of parallel sides are cut along slanting planes parallel toeach other; the body of each plate being crossed by parallel channelsforming wide weight-reducing hollow spaces.

According to a structural variant, while keeping the anchored refractorybricks unchanged, the order of complementary refractory bricks may beeliminated, while the plates assume, in this case, preferably a planshape with a square outline and rest, by ledge seats formed at theirfour vertices, on the anchored brick shoulders.

Another feature according to the present improve ment derives from thestructure of the refractory plates which, in any case, is box-shaped andhence made stiff in order to be sturdier and at the same time lighter inweight.

A further feature of the improvement derives from the open structureshape, substantially with a U outline, of the metal hooks which anchoreach refractory brick with respect to the load bearing beams; the shapeof said hooks being the most rational to co-operate with said anchoredbricks, as it will be described Additonal particular features of theinvention will be seen from the specification and the drawings, whichare annexed only for an illustrative purpose, and wherein:

FIG. 1 represents a furnace provided with a crown according to theinvention, in a vertical cross sectional view;

FIG. 2 is a partial vertical cros sectional view of the furnace crownalone, along line 11- of FIG. 1;

FIG. 3 is a top plan view of same crown;

FIG. 4 is a plan view of a refractory plate;

FIG. 5 is an end view of same plate of FIG. 4;

FIG. 6 is a side view of the end of the same plate;

FIGS. 7 and 8 are elevational views, rotated to each other, of a firstshape of an anchored refractory brick;

FIGS. 9 and 10, similar to the preceding two figures, illustrate avariant of some details of said brick;

FIGS. 11 and 12 are side views of a complementary brick;

FIG. 13 is a perspective view of an anchoring hook for the bricksaccording to FIGS. 7 to 10;

FIG. 14 is plan view of a refractory plate according to a variant;

FIG. 15 illustrates the same plate inverted through FIG. 16 is a sideview of the plate of FIGS. 14 and 15;

FIG. 17 illustrates schematically and in a plan view the assembly of aplate of FIGS. 14 to 16; and

FIG. 18 is a side elevation view of a detail of FIG. 17.

With reference to FIGS. 1, 2, and 3, the furnace port, defined by thefloor A and side walls B of suitable masonry, is at the top defined bythe suspended crown according to the invention, which comprises aplurality of iron beams 20 with respect to which refractory bricks 22(FIGs. 2, 3, 7, 8, 9, 10) are suspended by means of hooks 21.

Each, substantially prismatic, brick 22 is provided, at one of its ends22a, with symmetrical and opposed projections 22b forming angled seats,with an acute angle, suitable to retain the horizontal branch 21a of asubstantially U outlined hook 21. Ends 21b of a pair of hooks 21 usedfor each brick 22 or 23, engage the side edges 20a (FIGS. 1 and 2) ofthe lower flange of each beam 20. The end 22d of each brick 22 or 23 hasa T- shaped outline and with its side projections 22d, forms horizontalbearing brackets for the edges 24a of refractory plates 24.

According to a first variant, FIGS. 7 and 8, the upper end 23a of eachbrick, instead of the symmetrical projections 2211, presents an invertedT-shaped cut 2317 which forms a hollow seat for a pair of hooks 21engaging, as described, the lower flange of beam 20.

Each refractory brick 22 and 23 having its central part shaped as aretangular prism, is provided, on the sides at right angles with respectto those terminatng with the side projections 22d, respectively, withsymmetrical grooves 22e, 232, and teeth 22f, 23f.

Refractory bricks 25 (FIGS. 11 and 12) cooperate with bricks 22, 23, andpresent a lower end 25a having the T-shaped outline as the one alreadydescribed; the

sides provided with grooves 25c and teeth 25f but without retainingmeans for the hooks 21.

Courses of bricks 22, 25 are mounted in side-by-side rows directly underbeams 20, as represented on FlGS. 1, 2, and 3.

Bricks 23 are anchored and they are easily and rapidly hooked to beamsforming, with parallel beams, the load bearing framework for thesuspended crown; two or more of the bricks 25, mutually fixed along thesides and fixed with respect to the cooperating quoins 23, are partiallyself-supporting. The order of the two cooperating quoins form opposedand symmetrical bearing brackets 22d for the ledge edges 24a of plates24 of refractory material.

Each plate 24 (FIGS. 4, 5, 6) has a box-shaped body, namely, a bodyprovided with wide channels 24d which reduce its weight while providingthe assembly with a remarkable stiffness. Each plate 24 further presentsend edges 240 at 90 with respect to the toothed edges 24a cut with aslanting outline in order to permit assembly by coupling of the edgeswith the preceding and fol lowing plates.

The toothed outline 24a of the plates, which rest on brackets 22d ofbricks, and the slanting outline, with the broken line 24c, 24d of sameplates reduce appreciably, if they do not eliminate, the thermal lossesby blow-by of the furnace. The channels 24b of said plates createfurther hollow spaces which are useful for the thermal insulation of thecrown and to admit in said channels the smoke from the burners of thefurnace to obtain direct heating of the crown.

According to the structure of the suspended crown, and retaining the useof the bearing bricks 22 or 23 and the framework of beams 20 unchanged,the refractory plates 26 may be made with a preferably quadrangular planshape structure, with angles at the vertices 26a cut at right angles, asrepresented in FIGS. 14 to 17. In such case, with the eleimination ofthe intermediate bricks 25, the suspended crown of the furnace assumes amore compact structure which is less subject to movement; the bearingbricks 22 or 23 are provided at their lower ends with a head 23g havingfour bearing edges.

The refractory plates 26 are provided with ribs 26b weight-reducingcavities 26c. They further present parallel edges 26:] profiled withopposed teeth so that the perimetrical edges of each plate 26 may beoverlapped with respect to the edges of the preceding and followingplates in a horizontal plane.

Obviously, in both the case of plates 24 and the case of plates 26 therespective rectangular plan shape and quadrangular plan shape ispreferred but not limiting, in that it may vary according to theextension of the crown and, hence, to the furnace capacity.

In both the described cases the particular features of the suspendedcrown remain; said features have already been mentioned and aresummarized as follows:

crown formed by three or two pressed modular elements;

rapid assembling of the crown due to the rapid and easy assembly of theelements which form it;

hooks to retain the bearing bricks and having .a U shaped profile,namely, open and hence easily disengageable from the corresponding hookseats formed by the lower flange of the beams;

a compact structure of the crown which prevents es cape of heat;

the crown may be heated by the use of plates 24 of the type illustratedon FIGS. 4, 5, and 6, that is, provided with channels 24b which arecoincident between the various plates of each course included betweentwo parallel beams 20;

savings in construction deriving from the use of modular elements andthe rapidity of assembling and possible replacement of same.

Obviously, the improvement according to the invention is not limitedparticularly to the embodiments represented and described herein onlyfor illustrative purposes, but it comprises all the variants dependingfrom the described solutions and the improvements which may necessarilyor advantageously result from the practical application.

What is claimed is:

l. A furnace crown suspended from parallel fixed beams, said crowncomprising:

a. hook-shaped anchors adapted to engage the flanges of the beams anddepend therefrom,

b. a plurality of anchored refractory bricks, of generally rectangularcross-sectional shape, spaced apart along the length of each beam, eachanchored brick being formed at its upper end with means foraccommodating said anchors and at its lower end with flanges projectingfrom two opposite sides of said anchored brick, the other opposite sidesof said anchored brick each being formed with horizontally extendinggrooves and projections,

c. a plurality of non-anchored refractory bricks, of generallyrectangular cross-sectional shape, each being devoid of means at itsupper end for accommodating said anchors, each of said non-anchoredbricks being formed at its lower end with flanges projecting from twoopposite sides of said brick, the other two opposite sides of saidnon-anchored brick each being formed with horizontally extending groovesand projections, at least one of said non-anchored bricks being arrangedbetween each two successive anchored bricks with the grooves andprojections of the non-anchored brick intermeshed with the grooves andprojections of bricks on each side of the non-anchored brick to therebyform parallel rows of bricks, and

d. a plurality of generally rectangular refractory plates each extendingbetween two of said rows of bricks, the ends of each plate resting uponthe projecting flanges of said bricks.

2. A furnace crown as defined in claim 1 wherein each of said anchors isgenerally U-shaped so as to present a central horizontal portion, andsaid means for accommodating said anchors comprises a cavity, in theupper end of each anchored brick, having the shape of an inverted T,each end of the cross-member of the T being adapted to accommodate ahorizontal portion of one of said anchors.

3. A furnace crown as defined in claim 1 wherein each of said plates isformed with through channels oriented in the direction of said rows ofbricks, the plates between each two rows of bricks being arrangedsideby-side with the channels in each plate communicating with thechannels in the adjacent plates.

4. A furnace crown as defined in claim 1 wherein the sides of each ofsaid plates at which said channels terminate are slanted with respect tothe upper and lower faces of the plate, the ends of each plate whichrest upon said brick flanges being of stepped configuration.

6 5. A furnace crown suspended from parallel fixed brick, and beams,said crown comprising: 0. a plurality of generally rectangular plates,each a. hook-shaped anchors adapted to engage the plate extendingbetween at least two of said bricks flanges of the beams and dependtherefrom, and resting upon opposed flanges of the bricks beb. aplurality of anchored refractory bricks, of gener- 5 tween which it islocated.

ally rectangular cross-sectionalshape,spaced apart 6. A furnace crown asdefined in claim 5 wherein along the length of each beam, each anchoredeach corner of each of said plates is formed with a genbrick beingformed at its upper end with means for erally rectangular notch foraccommodating a portion accommodating said anchors and at its lower endof a brick above said flanges. with flanges projecting from all foursides of said 10

1. A furnace crown suspended from parallel fixed beams, said crowncomprising: a. hook-shaped anchors adapted to engage the flanges of thebeams and depend therefrom, b. a plurality of anchored refractorybricks, of generally rectangular crOss-sectional shape, spaced apartalong the length of each beam, each anchored brick being formed at itsupper end with means for accommodating said anchors and at its lower endwith flanges projecting from two opposite sides of said anchored brick,the other opposite sides of said anchored brick each being formed withhorizontally extending grooves and projections, c. a plurality ofnon-anchored refractory bricks, of generally rectangular cross-sectionalshape, each being devoid of means at its upper end for accommodatingsaid anchors, each of said non-anchored bricks being formed at its lowerend with flanges projecting from two opposite sides of said brick, theother two opposite sides of said non-anchored brick each being formedwith horizontally extending grooves and projections, at least one ofsaid non-anchored bricks being arranged between each two successiveanchored bricks with the grooves and projections of the non-anchoredbrick intermeshed with the grooves and projections of bricks on eachside of the non-anchored brick to thereby form parallel rows of bricks,and d. a plurality of generally rectangular refractory plates eachextending between two of said rows of bricks, the ends of each plateresting upon the projecting flanges of said bricks.
 2. A furnace crownas defined in claim 1 wherein each of said anchors is generally U-shapedso as to present a central horizontal portion, and said means foraccommodating said anchors comprises a cavity, in the upper end of eachanchored brick, having the shape of an inverted T, each end of thecross-member of the T being adapted to accommodate a horizontal portionof one of said anchors.
 3. A furnace crown as defined in claim 1 whereineach of said plates is formed with through channels oriented in thedirection of said rows of bricks, the plates between each two rows ofbricks being arranged side-by-side with the channels in each platecommunicating with the channels in the adjacent plates.
 4. A furnacecrown as defined in claim 1 wherein the sides of each of said plates atwhich said channels terminate are slanted with respect to the upper andlower faces of the plate, the ends of each plate which rest upon saidbrick flanges being of stepped configuration.
 5. A furnace crownsuspended from parallel fixed beams, said crown comprising: a.hook-shaped anchors adapted to engage the flanges of the beams anddepend therefrom, b. a plurality of anchored refractory bricks, ofgenerally rectangular cross-sectional shape, spaced apart along thelength of each beam, each anchored brick being formed at its upper endwith means for accommodating said anchors and at its lower end withflanges projecting from all four sides of said brick, and c. a pluralityof generally rectangular plates, each plate extending between at leasttwo of said bricks and resting upon opposed flanges of the bricksbetween which it is located.
 6. A furnace crown as defined in claim 5wherein each corner of each of said plates is formed with a generallyrectangular notch for accommodating a portion of a brick above saidflanges.